HYBRID DRIVE SYSTEM WITH REACH EXTENSION, CONTROL METHOD AND CRANE

Abstract

The invention relates to a hybrid drive system with range extension, a control method, and a crane, all belonging to the technical field of construction machinery. The hybrid drive system with range extension comprises a traction battery, an all-in-one controller, a first electric motor, a second electric motor, and an internal combustion engine, wherein the first electric motor is connected to the drive mechanism of the undercarriage, the internal combustion engine is connected to the second electric motor, and the second electric motor is connected to the operating mechanism of the superstructure, and wherein the traction battery, the first electric motor, and the second electric motor are connected to the all-in-one controller, and the all-in-one controller is connected to an external power source.When operating the upper structure, there is a choice of plug-in working mode, all-electric working mode, all-hydraulic working mode and hybrid working mode, and when driving the lower vehicle, there is a choice of all-electric driving mode and extended-range driving mode, which is beneficial for increasing the efficiency of the combustion engine, reducing fuel consumption and exhaust emissions and enhancing environmental protection.

Description

Field of the invention

[0001] The invention relates to the technical field of construction machinery, in particular a hybrid drive system with range extension, a control method and a crane. State of the art

[0002] With the continuous development of science and technology, the world is increasingly concerned with issues such as environmental management and energy scarcity. China is constantly paying attention to the energy consumption of the construction machinery industry. The construction machinery industry is developing toward energy conservation, emission reduction, and green environmental protection.

[0003] Currently, conventional mobile cranes use the internal combustion engine to drive the traveling operation of the chassis and the loading operation of the upperstructure, which require different power. The power of the traveling operation of the chassis is much higher than that of the loading operation of the upperstructure. The internal combustion engine must be matched to the traveling operation of the chassis. During loading operation of the upperstructure, the internal combustion engine often cannot operate in the high-efficiency range due to the high power, resulting in higher fuel consumption. The larger the tonnage, the more obvious the performance difference. High-tonnage cranes usually use dual engines installed on the chassis and upperstructure to meet the power requirements of traveling operation and loading operation. However, the cost and weight of the entire machine will be increased accordingly.Long-term operation of the internal combustion engine is accompanied by the emission of large amounts of harmful gases, which negatively impacts economic efficiency. Noise during driving and operation also affects the driver and the environment.

[0004] To solve this problem, cranes powered by electricity, or plug-in hybrid cranes, are entering the market. Due to their short battery life, purely electric cranes are less adaptable to road travel and charging operations. The combustion engine of a plug-in hybrid crane's chassis often cannot operate at peak efficiency during charging operations.

[0005] The existing cranes are mainly divided into single-engine cranes and twin-engine cranes. As in Fig. As shown in Figure 1, in a single-engine crane, the engine generates the driving force for the chassis. During loading, the engine also drives the hydraulic pump via the clutch, gearbox, and auxiliary drive. As shown in Fig. As shown in Figure 2, in the twin-engine crane, the chassis engine and the superstructure engine each generate a drive force for the travel operation of the chassis and the loading operation of the superstructure.

[0006] The single-engine crane has the following disadvantages: 1) The difference in power requirements between traveling and loading operations is large, and a single power system cannot accommodate both, resulting in high fuel consumption during uppercarriage loading operations; 2) The engine runs at low speed for a long time during uppercarriage loading operations, resulting in low exhaust gas temperatures, prone to carbon deposition, and complicated emission control standards; and 3) During uppercarriage loading operations, the idling of relative components such as the air compressor, steering pump, and air conditioning compressor leads to energy waste. The twin-engine crane has the following disadvantages: 1) The structural arrangement of the twin-engine crane is complex and occupies a lot of space; and 2) The maintenance cost of the two engines is high. Object of the invention

[0007] To overcome the deficiencies of the prior art, the invention provides a range-extending hybrid drive system, a control method, and a crane. During operation of the upper structure, plug-in working mode, pure electric working mode, pure hydraulic working mode, and hybrid working mode are available for selection. During travel of the lower structure, pure electric travel mode and range-extended travel mode are available for selection. This is beneficial for increasing the efficiency of the internal combustion engine, reducing fuel consumption and exhaust emissions, and enhancing environmental protection.

[0008] The invention provides the following technical solution: First, the invention provides a range-extended hybrid propulsion system comprising a propulsion battery, an all-in-one controller, a first electric motor, a second electric motor, and an internal combustion engine, wherein the first electric motor is connected to the travel mechanism of the lower vehicle, wherein the internal combustion engine is connected to the second electric motor and the second electric motor is connected to the operating mechanism of the upper vehicle, and wherein the drive battery, the first electric motor and the second electric motor are connected to the all-in-one controller and the all-in-one controller is connected to an external power source.

[0009] Furthermore, the driving mechanism of the sub-vehicle has a transmission connected to the first electric motor, a transmission shaft connected to the transmission, and a drive axle connected to the transmission shaft.

[0010] Furthermore, the internal combustion engine is arranged in the superstructure and connected to a first clutch, wherein the first clutch is connected to the second electric motor and the second electric motor is connected to a second clutch, and wherein the second clutch is connected to the operating mechanism of the superstructure.

[0011] Furthermore, the operating mechanism of the superstructure includes a hydraulic pump and a rotating device, a luffing device, a lifting device, a telescopic arm and chassis legs which are driven by the hydraulic pump.

[0012] Furthermore, the all-in-one controller is connected to the drive battery via the BMS and the all-in-one controller is connected to the first electric motor via the first MCU.

[0013] Furthermore, the all-in-one controller is connected to a center slewing gear and the center slewing gear is connected to the second electric motor via the second MCU.

[0014] Secondly, the invention provides a control method for the range-extended hybrid drive system, wherein the working modes of the upper structure include the plug-in working mode, the pure electric working mode, the pure hydraulic working mode, and the hybrid working mode, and the working modes of the lower structure include the pure electric traveling mode and the range-extended traveling mode.

[0015] Furthermore, when operating the superstructure: When an external power source is connected, it automatically enters the plug-in working mode, with the internal combustion engine and the second electric motor disengaged and the second electric motor and the upper structure operating mechanism engaged, the external power source driving the second electric motor via the all-in-one controller, which thus drives the upper structure operating mechanism, and at the same time the external power source charging the traction battery via the all-in-one controller; When the traction battery current is sufficient and exceeds the preset threshold A, the user can select the pure electric working mode, in which the internal combustion engine and the second electric motor are disengaged and the second electric motor and the upper structure operating mechanism are engaged, and the traction battery drives the second electric motor via the all-in-one controller, which thus drives the upper structure operating mechanism; and when the traction battery current is below the preset threshold A, the user is reminded to exit the pure electric working mode; When the user selects the pure hydraulic working mode, the internal combustion engine drives the operating mechanism of the superstructure via the rotor of the second electric motor; and when the current of the traction battery is low, the second electric motor can be used as a generator to charge the traction battery; and When the user selects the hybrid working mode, the internal combustion engine and the second electric motor are engaged, and the second electric motor and the upper structure operating mechanism are engaged, the internal combustion engine drives the upper structure operating mechanism through the rotor of the second electric motor, and at the same time, the second electric motor is driven in time according to the load conditions of the upper structure, the efficiency of the internal combustion engine, and the current of the traction battery to adjust the torque output of the internal combustion engine so that the internal combustion engine operates in the high-efficiency range.

[0016] Furthermore, when driving the sub-vehicle: If the traction battery current is sufficient and exceeds the specified threshold A, the user can select the pure electric driving mode, whereby the traction battery drives the first electric motor via the all-in-one controller, which thus drives the driving mechanism of the sub-vehicle, causing the entire vehicle to travel; if the traction battery current is below the specified threshold A, the user is reminded to exit the pure electric driving mode; and When the user selects the extended-range travel mode and the traction battery current is sufficient and above the designated threshold A, the traction battery drives the first electric motor via the all-in-one controller, which thus drives the traveling mechanism of the lower vehicle, causing the entire vehicle to travel; and when the traction battery current is below the designated threshold A, the internal combustion engine and the second electric motor are engaged, and the second electric motor and the operating mechanism of the upper vehicle are disengaged, whereby the internal combustion engine is started and drives the second electric motor to generate power and charge the traction battery via the all-in-one controller, and at the same time, it drives the first electric motor via the all-in-one controller, which thus drives the traveling mechanism of the lower vehicle, causing the entire vehicle to travel;When the traction battery current exceeds threshold B, the engine stops operating. The traction battery drives the first electric motor via the all-in-one controller, which drives the driving mechanism of the sub-vehicle, causing the entire vehicle to travel until the traction battery current falls below the predetermined threshold A, at which point the engine restarts and repeats this process. When the traction battery current is between threshold A and threshold B, the engine can start to generate power in time to meet the power requirements for starting the vehicle, thus preventing the traction battery from being consumed too quickly.

[0017] Thirdly, the invention provides a crane having the reach-extending hybrid drive system and using the control method to realize the operation of the upper structure and the traveling of the lower structure.

[0018] Compared with the prior art, the invention has the following advantages: (1) The driving of the sub-vehicle includes a pure electric driving mode and a range-extended driving mode. In pure electric driving mode, there is no fuel consumption. Since the internal combustion engine does not need to directly drive the vehicle, the output of the internal combustion engine does not need to be adjusted according to the drive power demand. The engine always operates in the high-efficiency range. The displacement and power of the internal combustion engine are smaller than those of conventional internal combustion engines in fuel vehicles, which reduces fuel consumption and exhaust emissions, thus saving energy and reducing emissions. When driving, the vehicle is driven by the electric motor, which achieves strong acceleration performance, low noise, and better driving comfort. (2) The operation of the upper structure includes plug-in working mode, pure electric working mode, pure hydraulic working mode, and hybrid working mode. The plug-in working mode and pure electric working mode have no fuel consumption. In the pure electric working mode, the internal combustion engine directly drives the operation of the upper structure, avoiding high-voltage system failure and product inability to work, thus increasing the work adaptability of the crane. In the hybrid working mode, the internal combustion engine and the electric motor work together. The torque is large and the work efficiency is high. The electric motor can regulate the torque of the internal combustion engine, thereby increasing the work efficiency of the internal combustion engine and reducing fuel consumption. Brief description of the drawings Fig. 1 a representation of the single-engine crane in the state of the art, Fig. 2 a representation of the twin-engine crane in the state of the art, Fig. 3 is a view of the range-extended hybrid drive system of the embodiment of the invention. Description of the preferred embodiments

[0019] The present invention will be described in more detail below in conjunction with the accompanying drawings. The following embodiments are only intended to more clearly illustrate the technical solutions of the present invention, but cannot be used to limit the scope of the present invention. Embodiment 1

[0020] Fig. 3 shows the embodiment of the range-extended hybrid drive system comprising a drive battery, an all-in-one controller, an electric motor 1, an electric motor 2, and an internal combustion engine.

[0021] The traction battery is located in the sub-vehicle and connected to the all-in-one controller via the BMS. The all-in-one controller is connected to a center slewing gear. The center slewing gear is connected to electric motor 2 via MCU2. The high voltage of the traction battery is transmitted to electric motor 2 via the BMS, the all-in-one controller, the center slewing gear, and MCU2. The all-in-one controller is connected to electric motor 1 via MCU1. Electric motor 1 is connected to the travel mechanism of the sub-vehicle. The travel mechanism of the sub-vehicle has a gearbox connected to electric motor 1, a transmission shaft connected to the gearbox, and a drive axle connected to the transmission shaft. The high voltage of the traction battery is transmitted to electric motor 1 via the BMS, the all-in-one controller, and MCU1.The electric motor 1 is connected to the drive axle via the gearbox and the gearbox shaft, which allows the sub-vehicle to drive.

[0022] The internal combustion engine is located in the upper structure and connected to a clutch 1. The clutch 1 is connected to the input shaft of the electric motor 2, and the output shaft of the electric motor 2 is connected to a clutch 2. The clutch 2 is connected to the operating mechanism of the upper structure. The operating mechanism of the upper structure includes a hydraulic pump connected to the clutch 2, and a rotating device, luffing device, lifting device, telescopic arm, and chassis legs driven by the hydraulic pump. The hydraulic pump can be driven by the electric motor 2 or by the internal combustion engine via the clutch 1 and the rotor of the electric motor 2. It can also be driven by both. The hydraulic pump drives the hydraulic system of the upper structure to perform rotating, luffing, lifting, and telescopic movements.At the same time, the hydraulic pump is connected to the center slewing gear and can also transmit hydraulic oil to perform the movements of the undercarriage's outrigger legs. The all-in-one controller can also be connected to an external power source to realize plug-in working mode.

[0023] In this embodiment, the internal combustion engine, electric motor 1, second electric motor 2, and traction battery are connected to the all-in-one controller via the MCU or BMS. The center slewing gear transmits the hydraulic pressure, high voltage, and communication signals of the uppercarriage and lowercarriage. The high-voltage transmission of the uppercarriage and lowercarriage can be realized by a high-voltage slip ring.

[0024] In this embodiment, the combustion engine is located in the superstructure, enabling the range extension of the lower vehicle and simultaneously driving the loading operation of the superstructure. The combustion engine of the superstructure is connected to the hydraulic pump via the clutch and the electric motor 2, thus realizing a parallel connection of the combustion engine and the electric motor.

[0025] In this embodiment, the traction battery, BMS, and all-in-one controller are located in the lower vehicle. In other embodiments, the traction battery, BMS, and all-in-one controller can also be located in the upper vehicle.

[0026] In other embodiments, the clutch 2 may be omitted. When the internal combustion engine drives the electric motor 2 to generate electricity and extend the range of the lower vehicle, the hydraulic pump of the upper structure runs continuously.

[0027] In other embodiments, one or more of the rotating, rocking and lifting movements may be driven by the electric motor. Embodiment 2

[0028] As in Fig. As shown in Figure 3, this embodiment provides a control method for the range-extended hybrid drive system described in Embodiment 1. The upper structure's working modes include the plug-in working mode, the pure electric working mode, the pure hydraulic working mode, and the hybrid working mode. The lower structure's working modes include the pure electric traveling mode and the range-extended traveling mode. (1) Operation of the superstructure

[0029] When an external power source is connected, it automatically enters the plug-in working mode. The coupling 1 between the internal combustion engine and the electric motor 2 is disengaged, and the coupling 2 between the electric motor 2 and the hydraulic pump is engaged. The external power source transmits the high voltage to MCU2 via the all-in-one controller and the intermediate gearbox. Under the control of MCU2, the electric motor 2 directly drives the hydraulic pump to work, so as to perform operations such as rotation, tipping, telescoping, lifting, and outrigger movement of the upper carriage. The internal combustion engine shuts off. At the same time, the external power source charges the drive battery via the all-in-one controller and the BMS.

[0030] When the traction battery current is sufficient and exceeds the preset threshold A (e.g., 30%), the user can select the pure electric working mode, similar to the plug-in working mode. Clutch 1 between the engine and electric motor 2 is disengaged, and clutch 2 between electric motor 2 and the hydraulic pump is engaged. The traction battery drives electric motor 2 via the BMS, all-in-one controller, center slewing gear, and MCU2. Electric motor 2 drives the hydraulic pump to perform slewing, luffing, telescoping, lifting, outrigger leg movements, etc. of the upper structure. When the traction battery current is below the preset threshold A, the user is reminded to exit the pure electric working mode.

[0031] The user can select the pure hydraulic working mode. Clutch 1 between the engine and electric motor 2 is engaged, and clutch 2 between electric motor 2 and the hydraulic pump is engaged. The engine drives the hydraulic pump through clutch 1, the rotor of electric motor 2, and clutch 2 to perform rotation, luffing, telescopic, lifting, outrigger leg movements, etc. of the upper structure. In this mode, electric motor 2 does not output power but can be used as a generator to charge the traction battery when the traction battery current is below the threshold C.

[0032] The user can select the hybrid working mode. Clutch 1 between the engine and the electric motor 2 is engaged, and clutch 2 between the electric motor 2 and the hydraulic pump is engaged. The engine drives the hydraulic pump to work via clutch 1, the rotor of the electric motor 2, and clutch 2. During this process, the electric motor 2 is driven in a timely manner according to the upper structure load conditions, the engine efficiency, and the traction battery current, adjusting the engine torque output to ensure that the engine operates at high efficiency and reduces fuel consumption and exhaust emissions. (2) Driving the sub-vehicle:

[0033] When the traction battery current is sufficient and exceeds the specified threshold A, the user can select the pure electric driving mode. The traction battery drives electric motor 1 via the BMS, the all-in-one controller, and MUC1. Electric motor 1 drives the entire vehicle for driving via the transmission, transmission shaft, and axle. When the traction battery current is below the specified threshold A, the user is reminded to switch the mode.

[0034] When the user selects the range-extended driving mode and the traction battery current is sufficient and above the designated threshold A, the traction battery drives the electric motor 1 via the BMS, the all-in-one controller, and MUC1, similar to the pure electric driving mode. The electric motor 1 drives the entire vehicle to drive via the gearbox, transmission shaft, and axle. When the traction battery current is below the designated threshold A, the clutch 1 between the engine and the electric motor 2 is engaged, and the clutch 2 between the electric motor 2 and the hydraulic pump is disengaged. The engine starts and drives the electric motor 2 to generate power and charge the traction battery via MCU2, the center pivot, the all-in-one controller, and the BMS. At the same time, it drives the vehicle to drive via MCU2, the center pivot, the all-in-one controller, and MCU1.If the traction battery current exceeds threshold B, the engine stops working. The traction battery drives the vehicle via electric motor 1 until the traction battery current falls below the specified threshold A. Then the engine starts again. This process is repeated. When the traction battery current is between threshold A and threshold B, the engine can start in time to generate power according to the power demand for the vehicle to start, thus preventing the traction battery from being consumed too quickly.

[0035] For example, the above threshold A is 30% and the threshold B is 90%. When the traction battery current is lower than 30%, the user must exit the pure electric working mode, and then the internal combustion engine starts to generate power. When the current is higher than 90%, it stops generating power. Embodiment 3

[0036] This embodiment provides a crane that has the reach-extending hybrid drive system described in Embodiment 1 and uses the control method described in Embodiment 2 to perform upper structure operation and lower structure travel. During upper structure operation, the user can select the electric motor to drive the upper structure hydraulic system or the internal combustion engine to drive the upper structure hydraulic system. The internal combustion engine can also be connected in parallel with the electric motor to provide hybrid drive to the upper structure. During lower structure travel, the electric motor is used to realize pure electric travel. During travel, the internal combustion engine can be used to generate electricity, thus providing electrical power for travel.Compared to the conventional chassis combustion engine, the superstructure combustion engine has lower power, so fuel consumption and CO2 emissions are low and cleanliness is increased.

[0037] The above description presents only the preferred embodiments of the present invention. It should be noted that several improvements and modifications can be made by those skilled in the art without departing from the technical principles of the present invention. These improvements and modifications should also be considered within the scope of the present invention.

Claims

[1] A range-extended hybrid drive system comprising a drive battery, an all-in-one controller, a first electric motor, a second electric motor, and an internal combustion engine, wherein the first electric motor is connected to the driving mechanism of the sub-vehicle, wherein the internal combustion engine is connected to the second electric motor and the second electric motor is connected to the operating mechanism of the superstructure, and wherein the drive battery, the first electric motor and the second electric motor are connected to the all-in-one controller and the all-in-one controller is connected to an external power source. [2] Hybrid drive system with range extension according to claim 1, characterized by that the driving mechanism of the sub-vehicle has a gearbox connected to the first electric motor, a gearbox shaft connected to the gearbox and a drive axle connected to the gearbox shaft. [3] Hybrid drive system with range extension according to claim 1, characterized by that the internal combustion engine is arranged in the superstructure and is connected to a first clutch, wherein the first clutch is connected to the second electric motor and the second electric motor is connected to a second clutch, and wherein the second clutch is connected to the operating mechanism of the superstructure. [4] Hybrid drive system with range extension according to claim 1, characterized by that the operating mechanism of the superstructure includes a hydraulic pump and a rotating device, a luffing device, a lifting device, a telescopic arm and chassis legs driven by the hydraulic pump. [5] Hybrid drive system with range extension according to claim 1, characterized bythat the all-in-one controller is connected to the drive battery via the BMS and the all-in-one controller is connected to the first electric motor via the first MCU. [6] Hybrid drive system with range extension according to claim 1, characterized by that the all-in-one controller is connected to a center slewing gear and the center slewing gear is connected to the second electric motor via the second MCU. [7] Control method for the range-extending hybrid drive system according to one of claims 1 to 6, characterized by that the working modes of the upper structure include plug-in working mode, pure electric working mode, pure hydraulic working mode and hybrid working mode, and the working modes of the lower structure include pure electric driving mode and range-extended driving mode. [8] Control method for the range-extending hybrid drive system according to claim 7, characterized bythat when operating the superstructure: When an external power source is connected, it automatically enters plug-in working mode, with the combustion engine and the second electric motor disengaged and the second electric motor and the operating mechanism of the superstructure are engaged, wherein the external power source drives the second electric motor via the all-in-one controller, which thus drives the operating mechanism of the superstructure, and at the same time the external power source charges the traction battery via the all-in-one controller; If the current of the traction battery is sufficient and above the preset threshold A, the user can select the purely electric working mode, wherein the internal combustion engine and the second electric motor are disengaged and the second electric motor and the upper structure operating mechanism are engaged, and wherein the traction battery drives the second electric motor via the all-in-one controller, which thus drives the upper structure operating mechanism; and when the traction battery current is below the predetermined threshold A, the user is reminded to exit the pure electric working mode; When the user selects the pure hydraulic working mode, the combustion engine drives the operating mechanism of the superstructure via the rotor of the second electric motor; and when the traction battery current is low, the second electric motor can be used as a generator to charge the traction battery; When the user selects the hybrid working mode, the combustion engine and the second electric motor is engaged and the second electric motor and the operating mechanism of the upper structure are engaged, wherein the internal combustion engine drives the operating mechanism of the upper structure via the rotor of the second electric motor, and at the same time, the second electric motor is driven in time according to the load conditions of the upper structure, the efficiency of the internal combustion engine and the current of the traction battery to adjust the torque output of the internal combustion engine so that the internal combustion engine operates in the high-efficiency range. [9] Control method for the range-extending hybrid drive system according to claim 7, characterized by that when driving the sub-vehicle: When the traction battery current is sufficient and exceeds the specified threshold A, the user can select the pure electric driving mode, where the traction battery drives the first electric motor via the all-in-one controller, which thus drives the driving mechanism of the sub-vehicle, thereby driving the entire vehicle; when the traction battery current is below the specified threshold A, the user is reminded to exit the pure electric driving mode; When the user selects the extended-range driving mode and the drive battery current is sufficient and above the designated threshold A, the drive battery drives the first electric motor via the all-in-one controller, which thus drives the driving mechanism of the sub-vehicle, causing the entire vehicle to drive; and When the traction battery current is below the predetermined threshold A, the internal combustion engine and the second electric motor are engaged, and the second electric motor and the upper carriage operating mechanism are disengaged, whereby the internal combustion engine is started and drives the second electric motor to generate power and charge the traction battery via the all-in-one controller, and at the same time, via the all-in-one controller, it drives the first electric motor, which thus drives the lower carriage traveling mechanism, causing the entire vehicle to travel; and when the traction battery current is above the threshold B, the internal combustion engine stops operating, where the drive battery drives the first electric motor via the all-in-one controller, which thus drives the traveling mechanism of the sub-vehicle, causing the entire vehicle to travel until the current of the traction battery is below the predetermined threshold A, at which point the engine restarts and this process is repeated; and when the current of the traction battery is between threshold A and threshold B, the engine can start to generate power in time according to the power requirement for starting the vehicle, so as to prevent the traction battery from being consumed too quickly. [10] A crane having the reach-extending hybrid drive system according to any one of claims 1 to 6 and using the control method according to any one of claims 7 to 9 to realize the operation of the upper structure and the traveling of the lower structure.

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